Apparatus for use in the manufacture of semi-conductor devices

ABSTRACT

When a semi-conductor slice is subjected to a manufacturing process to convert it to a plurality of semi-conductor components, it is then necessary to separate the semi-conductor components. The invention provides apparatus for doing this in which a pair of resilient diaphragms are used to sandwich the wafer, the diaphragms then being distended to crack the slice along previously scribed lines.

I United States Patent [151 3,667,66 1 Farmer June 6, 1972 [54]APPARATUS FOR USE IN THE I [56] References Cited MANUFACTURE OF SEIVH-UNITED STATES PATENTS CONDUCTOR DEVICES 3,507,426 4/1970 Bielen et al...225/96.5 X [72) Inventor: Francis Louis Farmer, 106 Holifast Rd,$182,873 5/1965 Kalvelage at X S tt c ldfi ld w i k hi England 3,493,1552/1970 Litant et al ..225/96.5 X

[22] Filed: 1970 Primary Examiner-Frank T. Yost 21 1 Appl 2 734Att0rneyH0lman, Glascock, Downing & Seebold 57 ABSTRACT [30] ForeignApplication Priority Data When a semi-conductor slice is subjected to amanufacturing May 1969 Great Bmam "22l8O/69 process to convert it to aplurality of semi-conductor c0m ponents, it is then necessary toseparate the semi-conductor [52] US. Cl ..225/2, 225/965 components Theinvention provides apparatus for doing this of w the wafer, thediaphragms then being distended to crack the slice along previouslyscribed lines.

5 Claims, 1 Drawing Figure PATENTEDJUH 61972 3.667, 661

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INVENTOR f l i MA 7244 ,ggwima ATRQNEYS APPARATUS FOR USE IN THEMANUFACTURE OF SEMI-CONDUCTOR DEVICES This invention relates toapparatus for, and a method of cracking a semi-conductor slice, whichhas previously been scribed, to divide the slice into a plurality ofsemi-conductor components.

Apparatus according to the invention includes a first resilientdiaphragm upon which, in use, a scribed semi-conductor slice issupported, a second resilient diaphragm engageable with the surface ofthe slice remote from said first diaphragm to maintain the slice inengagement with the first diaphragm and means for distending thediaphragms into a domed configuration so as to crack the slice along thescribed lines.

The invention further resides in a method of cracking a previouslyscribed semi-conductor slice including the steps of trapping the slicebetween a pair of resilient diaphragms and distending the diaphragms toa domed configuration to crack the slice along the scribed lines.

The accompanying drawing is a fragmentary diagrammatic sectional view ofapparatus according to one example of the invention.

The apparatus for cracking previously scribed semi-conductor slicesincludes a base 11 including a chamber 12 closed at one end by a rubberdiaphragm 13. The apparatus further includes a movable platen 14 whichis movable towards and away from the base 11, and which is provided, inits face presented to the diaphragm 13, with a recess 15. The recess 15is closed by a second rubber diaphragm 16 which is movable with themovable platen 14. Means (not shown) is provided for pumping air intothe chamber 11, and since the chamber 11 is closed by the diaphragm 13,then when the air pressure within the chamber 12 increases the diaphragm13 will be distended towards the movable platen 14 and will assume adomed configuration.

A slice 17 of silicon which has been treated to produce therein a P-Njunction is scribed on its upper surface to divide the slice into aplurality of rectangular P-N wafers each of which will constitute adiode. In order to crack the slice 17 along the scribed lines toseparate the P-N wafers from one another, the slice 17 is placed on thediaphragm 13 with its scribed surface uppermost. The movable platen 14is then moved into engagement with the base 11 so that the diaphragm 16traps the slice 17 in position on the diaphragm 13. Air is then admittedinto the chamber 12 under pressure, thereby causing the diaphragm 13 tobe distended towards the movable platen 14. Since the diaphragm 16 trapsthe slice 17 in facial contact with the diaphragm 13, then as thediaphragm 13 assumes its domed configuration, the slice l7 and thediaphragm 16 will also assume a domed configuration, and in so doing theslice 17 becomes cracked along the scribed lines. In order for a cleanfracture to be produced along the scribed lines, it is desirable thatthe slice 17 is subject to tensile bending stresses only, and not toshear stresses. For this reason the diaphragm 13 is made thicker thanthe diaphragm 16 so that the neutral plane of the laminated unitconstituted by the diaphragm 13, the slice 17 and the diaphragm 16,during distension thereof, occurs in the diaphragm 13.

If the diaphragm 13 were permitted to distend normally under the actionof air pressure in the chamber 12, then the amount of movement of theslice 17 at its edges would be less than that at the center of the sliceand unless the slice was of considerably smaller diameter than thediameter of the diaphragm 13 then the cracking of the slice at theperiphery thereof might produce wafers with damaged edges. In order toensure satisfactory cracking at the periphery of the slice 17, the baseof the recess 15 in the movable platen is so shaped that its radius ofcurvature is greater towards the periphery of the recess than at thecenter of the recess. Thus, when the diaphragm 13 is distended, theperiphery of the distended portion of the diaphragm 16 engages the baseof the recess 15, so that the peripheral portion of the diaphragm l6 andtherefore the slice 17 and the diaphragm l3, follow the shape of theperi heral ortion of the base of the recess 15.

en t e slice has been cracked, the pressure in the chamber 12 is reducedto atmospheric pressure so that the diaphragms l3, 16 return to theiroriginal positions. The movable platen 14 is then moved away from thebase 11 to expose the cracked wafers which are removed from thediaphragm 13 in any convenient manner.

It will be appreciated that the apparatus and procedure described abovecan be used to crack any form of scribed semi-conductor slice. Moreover,the cracked wafers could be of shapes other than rectangular, forexample triangular or rhombic. Furthermore, although compressed air isused to power the apparatus as described above, both other gases andliquids could be used.

Having thus described my invention what 1 claims as new and desire tosecure by Letters Patent is:

1. Apparatus for cracking a previously scribed semi-conductor slice,including a first resilient diaphragm upon which, in use, a scribedsemiconductor slice is supported, a second resilient diaphragmengageable with the surface of the slice remote from said firstdiaphragm to maintain the slice in engagement with the first diaphragmand means for distending the diaphragms into a domed configuration so asto crack the slice along the scribed lines, the relative thicknesses ofthe first and second diaphragms being such that the neutral plane of thelaminated unit constituted by the first and second diaphragms and thesemi-conductor slice occurs in one of the first and second diaphragms.

2. Apparatus as claimed in claim 1 including a body having therein arecess closed by the second diaphragm, the diaphragms being distendedinto said recess by application of a force to the first diaphragm.

3. Apparatus as claimed in claim 2 in which the recess is of generallydomed configuration with its radius of curvature greater towards theperiphery of the recess than at the center of the recess.

4. Apparatus as claimed in claim 1 in which the first diaphragm isthicker than the second diaphragm so that during cracking the neutralplane of the laminated unit constituted by the diaphragms and sliceoccurs in the first diaphragm.

5. A method of cracking a previously scribed semi-conductor sliceincluding the steps of trapping the slice between a pair of resilientdiaphragms and distending the diaphragms to a domed configuration tocrack the slice along the scribed lines the relative thicknesses of thetwo diaphragms being such that the neutral plane of the laminated unitconstituted by the two diaphragms and the slice occurs, duringdistention of the laminated units, in one of the diaphragms, and thescribed semi-conductor slice being positioned between the diaphragms insuch a manner that its scribed surface is outermost during thedistention of the diaphragms.

1. Apparatus for cracking a previously scribed semi-conductor slice,including a first resilient diaphragm upon which, in use, a scribedsemi-conductor slice is supported, a second resilient diaphragmengageable with the surface of the slice remote from said firstdiaphragm to maintain the slice in engagement with the first diaphragmand means for distending the diaphragms into a domed configuration so asto crack the slice along the scribed lines, the relative thicknesses ofthe first and second diaphragms being such that the neutral plane of thelaminated unit constituted by the first and second diaphragms and thesemiconductor slice occurs in one of the first and second diaphragms. 2.Apparatus as claimed in claim 1 including a body having therein a recessclosed by the second diaphragm, the diaphragms being distended into saidrecess by application of a force to the first diaphragm.
 3. Apparatus asclaimed in claim 2 in which the recess is of generally domedconfiguration with its radius of curvature greater towards the peripheryof the recess than at the center of the recess.
 4. Apparatus as claimedin claim 1 in which the first diaphragm is thicker than the seconddiaphragm so that during cracking the neutral plane of the laminatedunit constituted by the diaphragms and slice occurs in the firstdiaphragm.
 5. A method of cracking a previously scribed semi-conductorslice including the steps of trapping the slice between a pair ofresilient diaphragms and distending the diaphragms to a domedconfiguration to crack the slice along the scribed lines the relativethicknesses of the two diaphragms being such that the neutral plane ofthe laminated unit constituted by the two diaphragms and the sliceoccurs, during distention of the laminated units, in one of thediaphragms, and the scribed semi-conductor slice being positionedbetween the diaphragms in such a manner that its scribed surface isoutermost during the distention of the diaphragms.